What a phased migration covers
A phased Google Drive to Microsoft 365 migration moves your organisation in structured waves — rather than a single cutover — giving IT teams time to validate each stage and staff time to adapt. A full migration covers four areas:
Files and data
Google Shared Drives to SharePoint Sites, My Drive to OneDrive per user, format conversion from Google-native files (Docs, Sheets, Slides) to Microsoft Office formats.
Email and calendar
Gmail mailboxes to Exchange Online, Google Calendar to Outlook Calendar, Google Contacts to Outlook Contacts.
Permissions and sharing
Google Group sharing to Entra ID security groups, external sharing links replaced with SharePoint sharing links with expiry dates, sensitivity labels applied to confidential document libraries.
Applications and integrations
Google Meet replaced with Microsoft Teams, Google Forms rebuilt as Microsoft Forms, third-party applications reconfigured from Google Drive to SharePoint or OneDrive.
Why basic Google migration tools create security gaps
Google Takeout and manual export processes are not suitable for business migrations. Four specific risks:
Permission loss
Google Drive permissions are not preserved during export. Files migrated without a permissions mapping process become either fully private (breaking access) or fully public (creating data exposure), depending on destination SharePoint settings.
Format corruption
Google-native files converted via Takeout frequently lose formatting, embedded objects, comments, and revision history. For professional services businesses with years of client documents in Google Docs, this is a material business risk.
Silent file failures
Files with unsupported SharePoint characters in their names, paths exceeding 400 characters, or sizes exceeding 250GB fail to migrate without warning. Basic tools produce no failure report.
Broken external links
All Google Drive shared links stop working immediately when files are moved. Without a planned link replacement process, businesses are left with broken links in emails, contracts, and client documentation.
Quick win: Use Microsoft Migration Manager (free, built into the Microsoft 365 admin centre) — it supports Google Drive natively, preserves folder structures, maintains file metadata and timestamps, and produces a detailed migration error report.
The four-wave migration model
Wave 1 — IT and leadership (weeks 1–2)
Migrate the IT team and senior leadership first. Validate that SharePoint is correctly structured, OneDrive sync works on all device types, Teams channels are configured, and Exchange Online is receiving email. Fix issues before they affect the broader organisation.
Wave 2 — Pilot department (weeks 3–4)
Choose a department with low external communication dependency and an enthusiastic team leader. Validate the migration process at department scale — file access, shared drives, collaboration workflows, and application integrations.
Wave 3 — Core business functions (weeks 5–8)
Migrate remaining departments in sequence — typically finance, client services, and operations. Each department follows the same playbook: pre-migration communication, training session, migration weekend, Monday morning support presence, and a 2-week hypercare period.
Wave 4 — Final users and decommission (weeks 9–12)
Complete remaining user migrations, replace all Google Drive shared links with SharePoint equivalents, and set the Google Workspace decommission date. Maintain read-only Google Workspace access for 2–4 weeks post-decommission.
Five-step migration preparation plan
Step 1
Audit your Google Workspace environment — total data volume, Shared Drive structure, file format distribution, external sharing links, Google Forms, Google Sites, and any Google Vault compliance holds.
Step 2
Design the Microsoft 365 information architecture — map Google Shared Drives to SharePoint Sites, define document libraries, design Entra ID security groups to replace Google Groups, and plan sensitivity labelling for confidential content.
Step 3
Pre-migration remediation — identify and fix files with unsupported SharePoint characters, paths exceeding 400 characters, and Google-native files requiring format conversion before migration.
Step 4
Run the migration using Microsoft Migration Manager or a third-party tool (ShareGate, AvePoint for complex environments). Validate file counts, open a sample of files per department, and confirm permissions reflect the intended access model.
Step 5
Change management and hypercare — communicate the change 2 weeks before each wave, run a 60-minute Teams training session 1 week before, provide a dedicated support channel on Monday morning of the cutover week, and maintain elevated support for 2 weeks post-migration.
Frequently asked questions
What is the best tool for migrating Google Drive to Microsoft 365?
Microsoft Migration Manager — built into the Microsoft 365 admin centre and free — is the recommended starting point. It supports Google Drive as a source, preserves folder structure and file metadata, and produces a migration error report. For complex environments (100+ users, multiple domains, large data volumes), third-party tools such as ShareGate or AvePoint provide more granular permissions mapping and scheduling.
How long does a Google Drive to Microsoft 365 migration take for an Australian SME?
For a typical 20–50 user business, a four-wave phased migration takes 8–12 weeks from project kick-off to Google Workspace decommission — 2–3 weeks for planning and remediation, 6–8 weeks for the four migration waves, and 1–2 weeks for validation and decommission.
Will I lose file permissions when migrating from Google Drive to SharePoint?
Yes, if using basic tools. Google Drive's individual sharing model does not map automatically to SharePoint's site-based permissions model. A managed migration uses a deliberate permissions mapping process — Google Groups to Entra ID security groups — to preserve the intended access model without recreating Google Drive's permission sprawl.
Can I run Google Workspace and Microsoft 365 at the same time during migration?
Yes — parallel running is standard during a phased migration. Budget for 4–8 weeks of dual licensing as the standard parallel window. Establish a clear rule about which environment to use for new files from the migration date to avoid duplication.
Do I need to migrate from Google Drive before deploying Microsoft 365 Copilot?
Yes. Microsoft 365 Copilot only works with content stored in SharePoint, OneDrive, Teams, and Exchange Online. It cannot access Google Drive. Migrating to SharePoint is a prerequisite for Copilot deployment — and how SharePoint is structured during the migration directly determines Copilot's effectiveness.
